Nb2O5 Blocking Layer for High Open-circuit Voltage Perovskite Solar Cells

A solution-processed Nb2O5 film was employed as a thin blocking layer (BL) in CH3NH3PbI3−xClx-based solar cells for the first time. A cell with Nb2O5 BL exhibited larger open-circuit photovoltage than a cell with conventional TiO2 BL. Dark current behavior suggests that recombination from F-doped tin oxide electrode to perovskite layer was efficiently blocked by the Nb2O5 BL.